Reaction of chiral α-chloro N-tert-butanesulfinyl ketimines with Grignard reagents afforded new chiral N-sulfinyl 2,2-disubstituted aziridines in good to excellent diastereomeric ratio (dr up to 98â:â2). The 1,2,2-trisubstituted aziridines were isolated in high overall yield (51â85%) and with excellent enantiomeric excess (>98% ee). The stereoselectivity obtained in the Grignard addition is rationalized by the coordinating ability of the α-chloro atom resulting in the opposite stereochemical outcome as observed for nonfunctionalized N-sulfinyl ketimines.
手性α-
氯代N-特丁基亚磺酰基
亚胺与Grignard试剂的反应,得到了新的手性N-亚磺酰基2,2-二取代
氮杂环丙烷,其非对映体比例良好至优秀(最高达98:2)。1,2,2-三取代
氮杂环丙烷的总产率很高(51-85%),并且具有极佳的立体选择性(>98% ee)。Grignard加成反应中获得的立体选择性,可归因于α-
氯原子的配位能力,导致了与非官能化N-亚磺酰基
亚胺相反的立体
化学结果。